狀態：alpha（實驗版）。 只在 Xiaomi 15（HyperOS 3、Android 16）實機驗證過。需要 Shizuku，不需要 root。 Status: alpha. Verified on one device only: Xiaomi 15 (HyperOS 3, Android 16). Needs Shizuku, no root.
⭐ 好用的話，請按右上角的 Star 給個星星！ 這是我們知道有人在用、繼續維護下去的最大動力。 ⭐ If this app is useful to you, please give it a Star (top-right). It's how we know people use it, and it keeps the project going.
藍牙喇叭正在放 YouTube Music，你一打開 Facebook／IG／TikTok 滑影片，影片聲音也跟著跑到藍牙喇叭。 Android 沒有「指定某個 App 從哪裡出聲」的設定（三星的「個別應用程式聲音」只有三星有）。 SplitAudio 讓 音樂 App 留在藍牙、其他所有 App 改走手機喇叭。
You are playing YouTube Music on a Bluetooth speaker, then open Facebook / Instagram / TikTok — and the video sound also goes to the speaker. Stock Android has no per-app output setting (Samsung's "Separate app sound" is Samsung-only). SplitAudio keeps the music app on Bluetooth and sends every other app to the phone speaker.
- 藍牙連著＋音樂 App 正在播 → 音樂 App 走藍牙，其他 App 全走手機喇叭。 While Bluetooth is connected and the music app is playing: music → Bluetooth, every other app → phone speaker.
- 音樂停 15 秒或藍牙斷開 → 規則拿掉，一切恢復原狀。講電話（含網路電話）時也會先拿掉。
- 別的 App 進入通話／語音對講（例如監視器 App 按麥克風）：Android 這時會把媒體改送到聽筒，所以先暫停音樂，結束後自動續播。 While another app is in a call / voice chat (e.g. a camera app's talk button) Android sends media to the earpiece, so the music is paused and resumed afterwards. Music stopped for 15 s, or Bluetooth gone → the rule is removed and audio behaves normally. Also removed during calls.
- 音量鍵：在走喇叭的 App 畫面按＝調手機喇叭（畫面提示「手機喇叭音量 xx%」）；在音樂 App／桌面按＝照常調藍牙。 Volume keys: in a speaker-routed app they change the phone speaker volume; in the music app / home screen they change Bluetooth as usual.
- 開影片不打斷音樂：Android 預設「別的 App 一開影片，音樂 App 就自己暫停」（播放權只給一個 App），光分流擋不住。 第一次分流時會打開 Android 內建的「多個 App 同時播放」（multi audio focus，Android 11 起內建、預設關），打開那一下音樂會停一秒，會自動按回播放。 這是系統設定、重開機仍有效；來電、鬧鐘照樣會讓全部暫停。不要的話在 App 按「開／關：開影片不打斷音樂」，之後就不會再自動打開。 移除 App 前想還原，先按一次關。 A video doesn't pause the music: by default, when another app starts a video it takes the audio focus and the music app pauses itself — routing alone can't stop that. The first time routing turns on, SplitAudio enables Android's built-in multi audio focus (Android 11+, off by default); the music pauses for a second at that moment and is resumed automatically. It is a system setting, so it survives reboot; calls and alarms still pause everything. Don't want it? Tap "開／關：開影片不打斷音樂" (toggle) in the app and it won't be switched on again. To restore the default before uninstalling, switch it off first.
- 故障安全：路由小程式一旦結束，規則跟著消失＝全部回到藍牙，不會變成沒聲音。 Fail-safe: if the helper process dies, its rule dies with it — audio falls back to Bluetooth, never to silence.
預設音樂 App＝YouTube Music（com.google.android.apps.youtube.music，以及 Morphe 修改版）。
Default music app = YouTube Music (plus the Morphe-patched package).
只在 Xiaomi 15（HyperOS 3、Android 16）實機驗證過。 Only verified on a Xiaomi 15 (HyperOS 3, Android 16).
- 打開「自訂模式」→「選每個 App 的輸出」：每個 App 可以選 預設（跟系統）／手機喇叭／藍牙／有線或 USB 耳機。 Turn on "Custom mode" → "Choose output for each app": every app can play on Default (follow the system) / Phone speaker / Bluetooth / Wired or USB headphones — like Samsung's "Separate app sound", on any phone with Shizuku.
- 選的裝置沒連著時，那個 App 就跟系統走（不會沒聲音）；講電話時規則先拿掉。 If the chosen device isn't connected, that app follows the system (never silence). The rule is removed during calls.
- 只列有桌面圖示的 App（不需要「讀取所有 App 清單」權限）。 Only apps with a launcher icon are listed (no "query all packages" permission).
- 簡單模式（音樂 App 走藍牙、其他走喇叭）仍是預設，升級後行為不變。 Simple mode (music app on Bluetooth, everything else on the speaker) stays the default, so upgrading changes nothing.
- 原理同下：App 把設定寫成
/data/local/tmp/approute.pkgmap，approute.sh startmap換成 uid 後起AppRoute map， 每種輸出各一組 RENDER 規則。 Same mechanism as below: the app writes/data/local/tmp/approute.pkgmap,approute.sh startmapturns package names into uids and startsAppRoute map, which registers one set of RENDER mixes per output device.
SplitAudio app ──Shizuku (shell user)──► /data/local/tmp/approute.sh start
│
▼
app_process AppRoute (route/AppRoute.java)
registers a system AudioPolicy:
RENDER mix, rule = RULE_MATCH_UID(<every app except the music app>)
device = built-in speaker
listens on 127.0.0.1:47821 (state / volume keys)
- shell 身分有
MODIFY_AUDIO_ROUTING，所以能註冊系統層的路由規則；有些廠牌 ROM 不理 App 自己指定的輸出裝置，但系統規則有效。 The shell user holdsMODIFY_AUDIO_ROUTING, so it can register a system-level routing policy. Some OEM ROMs ignore an app's ownsetPreferredDevice(), but a system policy is honoured. - 系統底層每條規則最多只收 20 個 uid（多的會被靜默丟掉），所以每 20 個 App 一條規則、最多 50 條（1000 個 App）。 Native AudioPolicy keeps at most 20 criteria per mix (extras are silently dropped), so apps are split into mixes of 20, up to 50 mixes (1000 apps).
- App 本身只負責：偵測「藍牙＋音樂在播」→ 經 Shizuku 把小程式放進
/data/local/tmp並啟動；小程式用setsid脫離，App 被系統殺掉也照跑。 The app only detects "Bluetooth + music playing", deploys the helper via Shizuku and starts it; the helper is detached withsetsid, so it keeps running even if the app is killed. It exits by itself after Bluetooth is gone for 2 min or the music app has been silent for 10 min.
從 0.2.1 起改用正式金鑰簽名；裝過更早測試版的要先解除安裝再裝。 Since 0.2.1 the APK is signed with a release key; if you installed an earlier test build, uninstall it first.
- 安裝並啟動 Shizuku（無線偵錯啟動即可）。Install and start Shizuku.
- 從 Releases 下載 APK 安裝。Install the APK from Releases.
- 打開 SplitAudio：按「① Shizuku 授權」；想用音量鍵功能再按「② 開啟無障礙」。 Open SplitAudio → "① Shizuku 授權" (grant Shizuku); optionally "② 開啟無障礙" (accessibility, for volume keys).
- 小米／HyperOS：自啟動打開、省電策略設「無限制」，不然常駐監看會被清掉。 Xiaomi / HyperOS: enable Autostart and set battery saver to "No restrictions", otherwise the monitor gets killed.
- 連藍牙、播 YouTube Music → 通知欄出現「SplitAudio：分流中」。 Connect Bluetooth, play YouTube Music → the notification shows "SplitAudio：分流中" (routing on).
換音樂 App：改 app/src/main/assets/approute.sh 的 MUSIC，以及 VolKeyService.kt 的 skip 清單。
To use another music app, edit MUSIC in app/src/main/assets/approute.sh and the skip list in VolKeyService.kt.
介面目前是繁體中文；歡迎英文翻譯 PR。The UI is Traditional Chinese for now; translation PRs welcome.
JDK 17、Android SDK（platforms;android-34、build-tools;34.0.0）、Gradle 8.9：
sh route/build_dex.sh # route/AppRoute.java -> app/src/main/assets/approute.dex
gradle assembleDebug
GitHub Actions 每次 push 都會從原始碼編出 APK（含路由小程式）。CI builds the APK (including the helper dex) from source on every push.
不連外網（INTERNET 權限只用在本機 127.0.0.1 溝通）、不收集任何資料。無障礙服務只攔音量鍵、只讀前景 App 的套件名稱，不讀畫面文字。
No network access beyond 127.0.0.1, no data collection. The accessibility service only filters volume keys and reads the
foreground package name; it does not read screen text. See SECURITY.md.
SplitAudio 目前有英文和繁體中文。想翻成你的語言？看 TRANSLATING.md，大約 15～30 分鐘。
SplitAudio is available in English and Traditional Chinese. Want it in your language? See TRANSLATING.md — it takes about 15–30 minutes.
MIT